Vehicles such as electric automobiles and hybrid automobiles are equipped with a power conversion device performing power conversion between direct-current power and altering-current power, for example. Patent Literature 1 (PTL 1) discloses a power conversion device that has a case and an outer refrigerant pipe connected to the case from the outside. The outer refrigerant pipe is fixed to the case by bolts.
An O-ring is disposed between the outer refrigerant pipe and the case. The O-ring adheres closely to both the case and the outer refrigerant pipe. This configuration ensures sealing properties between the case and the outer refrigerant pipe and suppresses entry of water or the like from the outside to inside of the case. The case is formed from aluminum, for example, by die-casting.